Variable camber trim units, aircraft comprising the same, and associated methods of operation

ABSTRACT

A variable camber trim unit comprises a housing, an input gear, and an output gear. The input gear and the output gear are rotatably supported by the housing. The variable camber trim unit is selectively configurable to one of a coupled configuration or a decoupled configuration. When the variable camber trim unit is in the coupled configuration, rotation of the input gear relative to the housing causes rotation of the output gear relative to the housing. When the variable camber trim unit is in the decoupled configuration, rotation of the input gear relative to the housing does not cause rotation of the output gear, and the output gear is rotationally fixed relative to the housing.

FIELD

The present disclosure relates to flight-control surfaces of aircraft.

BACKGROUND

Variable camber flap systems of aircraft require the ability to actuate inboard and outboard flaps separately. In conventional systems, the inboard and outboard shafts of a variable camber trim unit are connected to each other by a clutch, comprising a set of friction disks, preloaded by a disk spring stack. These existing units are large, heavy, complex, and may result in differential rotation between the input shaft and the output shaft due to slippage of the clutch.

SUMMARY

Accordingly, apparatuses and methods, intended to address at least the above-identified concerns, would find utility.

The following is a non-exhaustive list of examples, which may or may not be claimed, of the subject matter, disclosed herein.

Disclosed herein is a variable camber trim unit that comprises a housing, an input gear, and an output gear. The input gear and the output gear are rotatably supported by the housing. The variable camber trim unit is selectively configurable to one of a coupled configuration or a decoupled configuration. When the variable camber trim unit is in the coupled configuration, rotation of the input gear relative to the housing causes rotation of the output gear relative to the housing. When the variable camber trim unit is in the decoupled configuration, rotation of the input gear relative to the housing does not cause rotation of the output gear, and the output gear is rotationally fixed relative to the housing.

The housing provides structure for rotatably supporting the input gear, the output gear, and other structures of the variable camber trim unit of examples disclosed herein. When the input gear is coupled to an upstream structure for inputting a rotational input to the variable camber trim unit, the input gear transfers the rotational input to a downstream structure via the output gear when the variable camber trim unit is in the coupled configuration. By having a coupled configuration and a decoupled configuration, the variable camber trim unit provides for selective coupling and decoupling of rotational movement of structures coupled to the input gear and the output gear. Moreover, not only is the output gear rotationally decoupled from the input gear when the variable camber trim unit is in the decoupled configuration, but also the output gear is rotationally fixed relative to the housing, which is desirable in some configurations of flight-control surfaces with which the variable camber trim unit is used in one or more examples.

Also disclosed herein is a method of trimming flight-control surfaces. The method comprises configuring a variable camber trim unit to a coupled configuration and configuring the variable camber trim unit to a decoupled configuration. The variable camber trim unit comprises a housing, an input gear, and an output gear. The input gear is rotatably supported by the housing. The output gear is rotatably supported by the housing. When the variable camber trim unit is in the coupled configuration, rotation of the input gear relative to the housing causes rotation of the output gear relative to the housing. When the variable camber trim unit is in the decoupled configuration, rotation of the input gear relative to the housing does not cause rotation of the output gear, and the output gear is rotationally fixed relative to the housing.

By having a coupled configuration and a decoupled configuration, the variable camber trim unit provides for selective coupling and decoupling of rotational movement of structures coupled to the input gear and the output gear of the variable camber trim unit. Moreover, not only is the output gear rotationally decoupled from the input gear when the variable camber trim unit is in the decoupled configuration, but also the output gear is rotationally fixed relative to the housing, which is desirable in some configurations of flight-control surfaces with which the variable camber trim unit is used in one or more examples.

Also disclosed herein is an aircraft that comprises a fuselage and a wing, supported by the fuselage. The wing comprises an inboard flight-control surface, an outboard flight-control surface, and a variable camber trim unit. The inboard flight-control surface and the outboard flight-control surface are movable relative to the fuselage. The variable camber trim unit is coupled to the inboard flight-control surface and to the outboard flight-control surface. The variable camber trim unit is selectively configurable to one of a coupled configuration or a decoupled configuration. When the variable camber trim unit is in the coupled configuration, the outboard flight-control surface is coupled to the inboard flight-control surface, such that when the inboard flight-control surface moves relative to the fuselage, the outboard flight-control surface also moves relative to the fuselage. When the variable camber trim unit is in the decoupled configuration, the outboard flight-control surface is decoupled from the inboard flight-control surface, such that when the inboard flight-control surface moves relative to the fuselage, the outboard flight-control surface is fixed relative to the fuselage.

By having a coupled configuration and a decoupled configuration, the variable camber trim unit provides for selective coupling and decoupling of the inboard flight-control surface and the outboard flight-control surface. Moreover, not only is the outboard flight-control surface decoupled from the inboard flight-control surface when the variable camber trim unit is in the decoupled configuration, but also the outboard flight-control surface is fixed relative to the fuselage, which is desirable in some configurations of flight-control surfaces of aircraft.

Also disclosed herein is a method of operating an aircraft is disclosed. The method comprises configuring a variable camber trim unit of the aircraft to a coupled configuration and configuring the variable camber trim unit to a decoupled configuration.

By having a coupled configuration and a decoupled configuration, the variable camber trim unit of the aircraft provides for selective coupling and decoupling of the inboard flight-control surface and the outboard flight-control surface of the aircraft. Moreover, not only is the outboard flight-control surface decoupled from the inboard flight-control surface when the variable camber trim unit is in the decoupled configuration, but also the outboard flight-control surface is fixed relative to fuselage, which is desirable in some configurations of flight-control surfaces of aircraft.

BRIEF DESCRIPTION OF THE DRAWINGS

Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and where like reference characters designate the same or similar parts throughout the several views. In the drawings:

FIG. 1 is a block diagram of a variable camber trim unit, according to one or more examples of the subject matter, disclosed herein;

FIG. 2 is a schematic, isometric view of the variable camber trim unit of FIG. 1, according to one or more examples of the subject matter, disclosed herein, with the variable camber trim unit shown in the coupled configuration;

FIG. 3 is a schematic, fragmentary, cross-sectional, side view of the variable camber trim unit of FIG. 1, according to one or more examples of the subject matter, disclosed herein, with the variable camber trim unit shown in the coupled configuration;

FIG. 4 is a schematic, fragmentary, cross-sectional, side view of the variable camber trim unit of FIG. 1, according to one or more examples of the subject matter, disclosed herein, with the variable camber trim unit shown in the decoupled configuration;

FIG. 5 is a schematic, fragmentary, partial cross-sectional, side view of a portion of the variable camber trim unit of FIG. 1, according to one or more examples of the subject matter, disclosed herein;

FIG. 6 is a schematic, isometric view of a portion of the variable camber trim unit of FIG. 1, according to one or more examples of the subject matter, disclosed herein;

FIG. 7 is a block diagram of a method of trimming flight-control surfaces, using the variable camber trim unit of FIG. 1, according to one or more examples of the subject matter, disclosed herein;

FIG. 8 is a block diagram of an aircraft comprising the variable camber trim unit of FIG. 1, according to one or more examples of the subject matter, disclosed herein;

FIG. 9 is a schematic, fragmentary, plan view of the aircraft of FIG. 8, according to one or more examples of the subject matter, disclosed herein;

FIG. 10 is a block diagram of a method of operating the aircraft of FIG. 9, according to one or more examples of the subject matter, disclosed herein;

FIG. 11 is a block diagram of aircraft production and service methodology; and

FIG. 12 is a schematic illustration of an aircraft.

DESCRIPTION

In FIGS. 1 and 8, referred to above, solid lines, if any, connecting various elements and/or components may represent mechanical, electrical, fluid, optical, electromagnetic and other couplings and/or combinations thereof. As used herein, “coupled” means associated directly as well as indirectly. For example, a member A may be directly associated with a member B, or may be indirectly associated therewith, e.g., via another member C. It will be understood that not all relationships among the various disclosed elements are necessarily represented. Accordingly, couplings other than those depicted in the block diagrams may also exist. Dashed lines, if any, connecting blocks designating the various elements and/or components represent couplings similar in function and purpose to those represented by solid lines; however, couplings represented by the dashed lines may either be selectively provided or may relate to alternative examples of the subject matter, disclosed herein. Likewise, elements and/or components, if any, represented with dashed lines, indicate alternative examples of the subject matter, disclosed herein. One or more elements shown in solid and/or dashed lines may be omitted from a particular example without departing from the scope of the subject matter, disclosed herein. Environmental elements, if any, are represented with dotted lines. Virtual (imaginary) elements may also be shown for clarity. Those skilled in the art will appreciate that some of the features illustrated in FIGS. 1 and 8 may be combined in various ways without the need to include other features described in FIGS. 1 and 8, other drawing figures, and/or the accompanying disclosure, even though such combination or combinations are not explicitly illustrated herein. Similarly, additional features, not limited to the examples presented, may be combined with some or all of the features shown and described herein.

In FIGS. 7, 10, and 11, referred to above, the blocks may represent operations and/or portions thereof and lines connecting the various blocks do not imply any particular order or dependency of the operations or portions thereof. Blocks represented by dashed lines indicate alternative operations and/or portions thereof. Dashed lines, if any, connecting the various blocks represent alternative dependencies of the operations or portions thereof. It will be understood that not all dependencies among the various disclosed operations are necessarily represented. FIGS. 7, 10, and 11 and the accompanying disclosure describing the operations of the method(s) set forth herein should not be interpreted as necessarily determining a sequence in which the operations are to be performed. Rather, although one illustrative order is indicated, it is to be understood that the sequence of the operations may be modified when appropriate. Accordingly, certain operations may be performed in a different order or simultaneously. Additionally, those skilled in the art will appreciate that not all operations described need be performed.

In the following description, numerous specific details are set forth to provide a thorough understanding of the disclosed concepts, which may be practiced without some or all of these particulars. In other instances, details of known devices and/or processes have been omitted to avoid unnecessarily obscuring the disclosure. While some concepts will be described in conjunction with specific examples, it will be understood that these examples are not intended to be limiting.

Unless otherwise indicated, the terms “first,” “second,” etc. are used herein merely as labels, and are not intended to impose ordinal, positional, or hierarchical requirements on the items to which these terms refer. Moreover, reference to, e.g., a “second” item does not require or preclude the existence of, e.g., a “first” or lower-numbered item, and/or, e.g., a “third” or higher-numbered item.

Reference herein to “one or more examples” means that one or more feature, structure, or characteristic described in connection with the example is included in at least one implementation. The phrase “one or more examples” in various places in the specification may or may not be referring to the same example.

As used herein, a system, apparatus, structure, article, element, component, or hardware “configured to” perform a specified function is indeed capable of performing the specified function without any alteration, rather than merely having potential to perform the specified function after further modification. In other words, the system, apparatus, structure, article, element, component, or hardware “configured to” perform a specified function is specifically selected, created, implemented, utilized, programmed, and/or designed for the purpose of performing the specified function. As used herein, “configured to” denotes existing characteristics of a system, apparatus, structure, article, element, component, or hardware which enable the system, apparatus, structure, article, element, component, or hardware to perform the specified function without further modification. For purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as being “configured to” perform a particular function may additionally or alternatively be described as being “adapted to” and/or as being “operative to” perform that function.

Illustrative, non-exhaustive examples, which may or may not be claimed, of the subject matter, disclosed herein, are provided below.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 2-4 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 comprises housing 124, input gear 102, and output gear 108. Input gear 102 is rotatably supported by housing 124. Output gear 108 is rotatably supported by housing 124. Variable camber trim unit 100 is selectively configurable to one of a coupled configuration or a decoupled configuration. When variable camber trim unit 100 is in the coupled configuration, rotation of input gear 102 relative to housing 124 causes rotation of output gear 108 relative to housing 124. When variable camber trim unit 100 is in the decoupled configuration, rotation of input gear 102 relative to housing 124 does not cause rotation of output gear 108, and output gear 108 is rotationally fixed relative to housing 124. The preceding portion of this paragraph characterizes example 1 of the subject matter, disclosed herein.

Housing 124 provides structure for rotatably supporting input gear 102, output gear 108, and other structures of variable camber trim unit 100 of examples disclosed herein. When input gear 102 is coupled to an upstream structure for inputting a rotational input to variable camber trim unit 100, input gear 102 transfers the rotational input to a downstream structure via output gear 108 when variable camber trim unit 100 is in the coupled configuration. By having a coupled configuration and a decoupled configuration, variable camber trim unit 100 provides for selective coupling and decoupling of rotational movement of structures coupled to input gear 102 and output gear 108. Moreover, not only is output gear 108 rotationally decoupled from input gear 102 when variable camber trim unit 100 is in the decoupled configuration, but also output gear 108 is rotationally fixed relative to housing 124, which is desirable in some configurations of flight-control surfaces with which variable camber trim unit 100 is used in one or more examples.

In one or more examples, input gear 102 and output gear 108 are spur gears. In one or more examples, when variable camber trim unit 100 is installed in an aircraft, input gear 102 and output gear 108 are coupled respectively to an input shaft and an output shaft that in turn are coupled, respectively, to an inboard flight-control surface and an outboard flight-control surface, as discussed herein.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises input idler gear 104, output idler gear 106, and shaft 118. Input idler gear 104 is rotatably supported by housing 124, is meshed with input gear 102, and comprises input-idler-gear interior splined surface 110. Output idler gear 106 is rotatably supported by housing 124, is coaxial with input idler gear 104, is meshed with output gear 108, and comprises output-idler-gear interior splined surface 112. Shaft 118 is translationally supported within housing 124, is coaxial with input idler gear 104 and with output idler gear 106, and comprises first exterior splined surface 120, having first-exterior-splined-surface maximum diameter, and second exterior splined surface 122, having a second-exterior-splined-surface maximum diameter. Housing 124 comprises anchor interior splined surface 116, coaxial with input idler gear 104 and with output idler gear 106. When variable camber trim unit 100 is in the coupled configuration, shaft 118 is positioned within housing 124, such that first exterior splined surface 120 of shaft 118 is engaged with input-idler-gear interior splined surface 110, first exterior splined surface 120 of shaft 118 is disengaged from anchor interior splined surface 116, and second exterior splined surface 122 of shaft 118 is engaged with output-idler-gear interior splined surface 112. When variable camber trim unit 100 is in the decoupled configuration, shaft 118 is positioned within housing 124, such that first exterior splined surface 120 of shaft 118 is disengaged from input-idler-gear interior splined surface 110, first exterior splined surface 120 of shaft 118 is engaged with anchor interior splined surface 116, and second exterior splined surface 122 of shaft 118 is engaged with output-idler-gear interior splined surface 112. The preceding portion of this paragraph characterizes example 2 of the subject matter, disclosed herein, wherein example 2 also encompasses example 1, above.

Input idler gear 104 and output idler gear 106 provide structure for transferring rotational input from input gear 102 to output gear 108, via shaft 118, when variable camber trim unit is in the coupled configuration. Shaft 118, via its exterior splines and their engagement with the interior splines of input idler gear 104, output idler gear 106, and housing 124 and via its translation within housing 124 enables the coupled and decoupled configurations of variable camber trim unit 100.

In one or more examples, input idler gear 104 and output idler gear 106 are pinion gears. The various splined surfaces, disclosed herein, take any suitable form and configuration for operative engagement with a corresponding splined surface. In one or more examples, each splined surface comprises a plurality of splines that are sized and shaped to selectively slide into engagement with a corresponding plurality of splines such that when two splined surfaces are operatively engaged, the two splined surfaces are coupled together and restricted from relative movement with respect to each other. Splines additionally or alternatively are described as elongate teeth or ridges.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 2-4 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises actuator 126, supported by housing 124 and configured to selectively translate shaft 118 from a retracted position, in which first exterior splined surface 120 is disengaged from anchor interior splined surface 116, to an extended position, in which first exterior splined surface 120 is engaged with anchor interior splined surface 116. The preceding portion of this paragraph characterizes example 3 of the subject matter, disclosed herein, wherein example 3 also encompasses example 2, above.

By including actuator 126, variable camber trim unit 100 is controllable to transition variable camber trim unit 100 to its decoupled configuration when desired by a user or otherwise responsive to input from a control system, such as a flight control system.

In one or more examples, actuator 126 is a hydraulic actuator and is tied to a hydraulic system of an aircraft when variable camber trim unit 100 is installed.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises shaft spring 128, positioned within housing 124 and biasing shaft 118 toward the retracted position. The preceding portion of this paragraph characterizes example 4 of the subject matter, disclosed herein, wherein example 4 also encompasses example 3, above.

By biasing shaft 118 toward its retracted position that thus variable camber trim unit 100 toward its coupled configuration, the coupled configuration is the default configuration. That is, selective actuation of actuator 126 causes variable camber trim unit 100 to transition to the decoupled configuration, and when actuator 126 is not actuated, shaft spring 128 causes variable camber trim unit 100 to transition to the coupled configuration.

In one or more examples, shaft spring 128 comprises a stack of Belleville washers that bias shaft 118 toward actuator 126. In one or more examples, shaft spring 128 comprises a coil spring biased to an extended configuration, thereby biasing shaft 118 toward actuator 126.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, actuator 126 comprises cylinder 130 and actuator piston 132, positioned within cylinder 130 and operatively engaged with shaft 118. When cylinder 130 is pressurized, actuator piston 132 translates toward anchor interior splined surface 116 and causes shaft 118 to translate toward the extended position. The preceding portion of this paragraph characterizes example 5 of the subject matter, disclosed herein, wherein example 5 also encompasses example 3 or 4, above.

By being pressure-actuated, variable camber trim unit 100 is controllable by a hydraulic or pneumatic system, such as a hydraulic system of an aircraft.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises pressure compensation chamber 166. Housing 124 comprises internal volume 170, within which shaft 118 is positioned. Pressure compensation chamber 166 is in fluidic communication with internal volume 170. When actuator piston 132 causes shaft 118 to translate toward the extended position, fluid from internal volume 170 flows into pressure compensation chamber 166. The preceding portion of this paragraph characterizes example 6 of the subject matter, disclosed herein, wherein example 6 also encompasses example 5, above.

Pressure compensation chamber 166 provides pressure relief within internal volume 170 when actuator piston 132 extends into internal volume 170. Accordingly, if a non-compressible fluid, such as a lubricating fluid, is utilized within internal volume 170 for lubrication of the components of variable camber trim unit 100 within housing 124, a portion of the non-compressible fluid is displaced to pressure compensation chamber 166, thereby avoiding pressure spikes within housing 124 when variable camber trim unit 100 is in the decoupled configuration and thus maintaining integrity of any seals associated with housing 124.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, pressure compensation chamber 166 comprises chamber piston 172 and chamber spring 174, biasing chamber piston 172 toward internal volume 170. The preceding portion of this paragraph characterizes example 7 of the subject matter, disclosed herein, wherein example 7 also encompasses example 6, above.

Accordingly, when variable camber trim unit 100 transitions to the decoupled configuration, fluid from internal volume 170 of housing 124 pushes against chamber piston 172 against the bias of chamber spring 174. As a result, a constant volume of the fluid is maintained. When variable camber trim unit 100 transitions to the coupled configuration, chamber spring 174 pushes chamber piston 172 toward internal volume 170 of housing 124 and thus pushes the fluid back into internal volume 170, again maintaining a constant volume of the fluid and maintaining integrity of any seals associated with housing 124.

In one or more examples, chamber spring 174 is a coil spring, biased to an extended configuration, thereby biasing chamber piston 172 toward internal volume 170 of housing 124.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises anchor aligner 134, positioned within housing 124 between input idler gear 104 and anchor interior splined surface 116. Anchor aligner 134 is configured to align first exterior splined surface 120 for engagement with anchor interior splined surface 116. The preceding portion of this paragraph characterizes example 8 of the subject matter, disclosed herein, wherein example 8 also encompasses any one of examples 2 to 7, above.

Anchor aligner 134 ensures that first exterior splined surface 120 of shaft 118 is aligned for operative engagement with anchor interior splined surface 116 so that variable camber trim unit 100 can transition from the coupled configuration to the decoupled configuration.

In one or more examples, anchor aligner 134 accommodates for up to a half-spline mismatch between the splines of anchor interior splined surface 116 and first exterior splined surface 120. When each of anchor interior splined surface 116 and first exterior splined surface 120 comprise eighteen splines, a mismatch of 10 degrees in either direction, for a total of a 20-degree range, is accommodated by anchor aligner 134.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, anchor aligner 134 comprises aligner body 136 and aligner springs 138. Aligner body 136 is coaxial with shaft 118 and comprises aligner interior splined surface 140. Aligner springs 138 are engaged between aligner body 136 and housing 124 and rotationally bias aligner interior splined surface 140 into alignment with anchor interior splined surface 116 when aligner interior splined surface 140 is engaged with first exterior splined surface 120. The preceding portion of this paragraph characterizes example 9 of the subject matter, disclosed herein, wherein example 9 also encompasses example 8, above.

By being rotationally spring-biased, aligner body 136 has a centering effect on shaft 118 when first exterior splined surface 120 is engaged with aligner interior splined surface 140 to ensure that first exterior splined surface 120 will operatively engage with anchor interior splined surface 116, and thus to ensure that variable camber trim unit 100 can transition to the decoupled configuration and effectively rotationally lock output gear 108 relative to housing 124. Accordingly, if variable camber trim unit 100 is configuring to the decoupled configuration and first exterior splined surface 120 is not precisely aligned for operative engagement with anchor interior splined surface 116, then anchor aligner 134 will rotate shaft 118 to ensure that first exterior splined surface 120 is aligned for operative engagement with anchor interior splined surface 116.

In one or more examples, as seen in FIG. 6, aligner body 136 comprises one or more lobes, extending from a central hub and positioned within one or more corresponding pockets of housing 124. Aligner springs 138 are positioned on and engaged with opposing sides of a lobe of aligner body 136 within the pockets of housing 124. In one more examples, aligner springs 138 are coil springs biased to an extended configuration, thereby by biasing a corresponding lobe of aligner body 136 to a central position within a corresponding pocket of housing 124.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, aligner interior splined surface 140 comprises aligner-interior-splined-surface first end 142 and aligner-interior-splined-surface second end 144. Input idler gear 104 is closer to aligner-interior-splined-surface first end 142 than to aligner-interior-splined-surface second end 144. Splines of aligner interior splined surface 140 are tapered at aligner-interior-splined-surface first end 142. The preceding portion of this paragraph characterizes example 10 of the subject matter, disclosed herein, wherein example 10 also encompasses example 9, above.

Because the splines of the aligner interior splined surface 140 are tapered at the first end, when variable camber trim unit 100 transitions to the decoupled configuration and shaft 118 translates toward anchor interior splined surface 116, anchor aligner 134 will accommodate first exterior splined surface 120 initially being misaligned with aligner interior splined surface 140. That is, the ends of the splines at the first end of aligner interior splined surface 140 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of aligner interior splined surface 140 as shaft 118 translates toward anchor interior splined surface 116.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, splines of aligner interior splined surface 140 are tapered at aligner-interior-splined-surface second end 144. The preceding portion of this paragraph characterizes example 11 of the subject matter, disclosed herein, wherein example 11 also encompasses example 10, above.

Because the splines of the aligner interior splined surface 140 are tapered at the second end, when variable camber trim unit 100 transitions to the coupled configuration and shaft 118 translates away from anchor interior splined surface 116, anchor aligner 134 will accommodate first exterior splined surface 120 initially being misaligned with aligner interior splined surface 140. That is, the ends of the splines at the second end of aligner interior splined surface 140 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of aligner interior splined surface 140 as shaft 118 translates away from anchor interior splined surface 116.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, each spline of anchor interior splined surface 116 comprises tapered end 146, facing input idler gear 104. The preceding portion of this paragraph characterizes example 12 of the subject matter, disclosed herein, wherein example 12 also encompasses any one of examples 2 to 11, above.

Because the ends of the splines of anchor interior splined surface 116 are tapered, when variable camber trim unit 100 transitions to the decoupled configuration and shaft 118 translates toward anchor interior splined surface 116, housing 124 will accommodate first exterior splined surface 120 initially being misaligned with anchor interior splined surface 116. That is, the tapered ends of the splines of anchor interior splined surface 116 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of anchor interior splined surface 116 as shaft 118 translates toward anchor interior splined surface 116.

By being tapered, it is meant that the corresponding end of a spline narrows to create ramped surfaces that converge toward each other.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, each spline of input-idler-gear interior splined surface 110 comprises distal end 148, facing away from output idler gear 106. Distal end 148 is tapered. The preceding portion of this paragraph characterizes example 13 of the subject matter, disclosed herein, wherein example 13 also encompasses any one of examples 2 to 12, above.

Because the distal ends of the splines of input-idler-gear interior splined surface 110 are tapered, when variable camber trim unit 100 transitions to the coupled configuration and shaft 118 translates away from anchor interior splined surface 116, input idler gear 104 will accommodate first exterior splined surface 120 initially being misaligned with input-idler-gear interior splined surface 110. That is, the tapered distal ends of the splines of input-idler-gear interior splined surface 110 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the spines of input-idler-gear interior splined surface 110 as shaft 118 translates away anchor interior splined surface 116.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, each spline of first exterior splined surface 120 comprises first-exterior-spline first end 150 and first-exterior-spline second end 152, spaced apart from each other. First-exterior-spline first end 150 is tapered, and first-exterior-spline second end 152 is tapered. The preceding portion of this paragraph characterizes example 14 of the subject matter, disclosed herein, wherein example 14 also encompasses any one of examples 2 to 13, above.

Because the first ends of the splines of first exterior splined surface 120 are tapered, when variable camber trim unit 100 transitions to the coupled configuration and shaft 118 translates away from anchor interior splined surface 116, shaft 118 will accommodate first exterior splined surface 120 initially being misaligned with input-idler-gear interior splined surface 110. That is, the first ends of the splines of first exterior splined surface 120 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of input-idler-gear interior splined surface 110 as shaft 118 translates away from anchor interior splined surface 116. Similarly, because the second ends of the splines of first exterior splined surface 120 are tapered, when variable camber trim unit 100 transitions to the decoupled configuration and shaft 118 translates toward anchor interior splined surface 116, the second ends of the splines of first exterior splined surface 120 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of anchor interior splined surface 116.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, input idler gear 104 further comprises axial bore 154. Shaft 118 extends through axial bore 154. Axial bore 154 comprises distal region 156, having a distal-region diameter, and proximal region 158, having a proximal-region diameter. Output idler gear 106 is closer to proximal region 158 than to distal region 156. Input-idler-gear interior splined surface 110 extends along only distal region 156 of axial bore 154. When variable camber trim unit 100 is in the decoupled configuration, second exterior splined surface 122 extends within proximal region 158 of axial bore 154. The preceding portion of this paragraph characterizes example 15 of the subject matter, disclosed herein, wherein example 15 also encompasses any one of examples 2 to 14, above.

Inclusion of proximal region 158 of axial bore 154 without input-idler-gear interior splined surface 110 enables input idler gear 104 and output idler gear 106 to be positioned in close proximity to each other within housing 124, thereby enabling variable camber trim unit 100 to be more compact.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, the proximal-region diameter is greater than the second-exterior-splined-surface maximum diameter. The preceding portion of this paragraph characterizes example 16 of the subject matter, disclosed herein, wherein example 16 also encompasses example 15, above.

By being greater in diameter than the second-exterior-splined-surface maximum diameter, proximal region 158 creates a volume, within which second exterior splined surface 122 extends without an interference or friction between second exterior splined surface 122 and input idler gear 104 when variable camber trim unit 100 is in the decoupled configuration.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, the proximal-region diameter is greater than the distal-region diameter. The preceding portion of this paragraph characterizes example 17 of the subject matter, disclosed herein, wherein example 17 also encompasses example 15 or 16, above.

By having the proximal region greater in diameter than the distal-region diameter, in one or more examples, the maximum diameters of first exterior splined surface 120 and second exterior splined surface 122 of shaft 118 are the same, resulting in easier and lower-cost manufacture of shaft 118.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, the first-exterior-splined-surface maximum diameter is identical to the second-exterior-splined-surface maximum diameter. The preceding portion of this paragraph characterizes example 18 of the subject matter, disclosed herein, wherein example 18 also encompasses any one of examples 15 to 17, above.

Again, having the maximum diameters of first exterior splined surface 120 and second exterior splined surface 122 identical, shaft 118 is easier and less expensive to manufacture than otherwise.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, shaft 118 further comprises collar 160. When variable camber trim unit 100 is in the coupled configuration, collar 160 engages output idler gear 106. When variable camber trim unit 100 is in the decoupled configuration, collar 160 is positioned within proximal region 158. The preceding portion of this paragraph characterizes example 19 of the subject matter, disclosed herein, wherein example 19 also encompasses any one of examples 15 to 18, above.

Collar 160 acts as a structural stop to define the extent of translation of shaft 118 away from anchor interior splined surface 116. That is, engagement between collar 160 and output idler gear 106 at least in part defines the coupled configuration of variable camber trim unit 100. In one or more examples, actuator 126 therefore bears no force of shaft spring 128 when variable camber trim unit 100 is in the coupled configuration. In one or more examples, a gap is present between actuator piston 132 and shaft 118 when variable camber trim unit 100 is in the coupled configuration. Moreover, because collar 160 fits within proximal region 158 of axial bore 154 of input idler gear 104, variable camber trim unit 100 is compact.

Collar 160 additionally or alternatively is described as a flange that extends radially from shaft 118.

Referring generally to FIG. 1 and particularly to, e.g., FIG. 3 for illustrative purposes only and not by way of limitation, shaft 118 further comprises collar 160. When variable camber trim unit 100 is in the coupled configuration, collar 160 engages output idler gear 106. The preceding portion of this paragraph characterizes example 20 of the subject matter, disclosed herein, wherein example 20 also encompasses any one of examples 2 to 18, above.

Collar 160 acts as a structural stop to define the extent of translation of shaft 118 away from anchor interior splined surface 116. That is, engagement between collar 160 and output idler gear 106 at least in part defines the coupled configuration of variable camber trim unit 100.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 2-5 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises distal proximity sensor 162, supported by housing 124 and configured to sense when shaft 118 is less than a threshold distance away from distal proximity sensor 162. When shaft 118 is less than the threshold distance away from distal proximity sensor 162, first exterior splined surface 120 is engaged with anchor interior splined surface 116 and is disengaged from input-idler-gear interior splined surface 110. The preceding portion of this paragraph characterizes example 21 of the subject matter, disclosed herein, wherein example 21 also encompasses any one of examples 2 to 20, above.

Distal proximity sensor 162 provides a signal that confirms when variable camber trim unit 100 is in the decoupled configuration, and thus distal proximity sensor 162 enables notification of a potential non-operational state of variable camber trim unit 100 such as if variable camber trim unit 100 is otherwise intended to be in the coupled configuration.

In one or more examples, distal proximity sensor 162 is an inductive proximity sensor or a magnetic proximity sensor.

Referring generally to FIG. 1 and particularly to, e.g., FIGS. 2-4 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises proximal proximity sensor 164, supported by housing 124 and configured to sense when shaft 118 is less than a threshold distance away from proximal proximity sensor 164. When shaft 118 is less than the threshold distance away from proximal proximity sensor 164, first exterior splined surface 120 is disengaged from anchor interior splined surface 116 and is engaged with input-idler-gear interior splined surface 110. The preceding portion of this paragraph characterizes example 22 of the subject matter, disclosed herein, wherein example 22 also encompasses any one of examples 2 to 21, above.

Proximal proximity sensor 164 provides a signal that confirms when variable camber trim unit 100 is in the coupled configuration, and thus proximal proximity sensor 164 enables notification of a potential non-operational state of variable camber trim unit 100 such as if variable camber trim unit 100 is otherwise intended to be in the decoupled configuration.

In one or more examples, proximal proximity sensor 164 is an inductive proximity sensor or a magnetic proximity sensor.

Referring generally to FIG. 1 and particularly to, e.g., FIG. 2 for illustrative purposes only and not by way of limitation, variable camber trim unit 100 further comprises rotational position sensor 168, supported by housing 124 and configured to sense a rotational position of input gear 102 relative to housing 124. The preceding portion of this paragraph characterizes example 23 of the subject matter, disclosed herein, wherein example 23 also encompasses any one of examples 2 to 22, above.

Rotational position sensor 168 provides signal indicative of the rotational position of input gear 102 and thus also of upstream structure coupled to input gear 102, such as an inboard flight-control surface. Accordingly, the rotational position of the upstream structure is able to be monitored via merely sensing the rotational position of input gear 102, which is much less complex than directly sensing the rotational position of a large structure, such as a flight-control surface.

In one or more examples, rotational position sensor is a rotary encoder.

Referring generally to FIG. 7 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, method 200 of trimming flight-control surfaces comprises (block 202) configuring variable camber trim unit 100 to the coupled configuration and (block 204) configuring variable camber trim unit 100 to the decoupled configuration. The preceding portion of this paragraph characterizes example 24 of the subject matter, disclosed herein, wherein example 24 also encompasses any one of examples 1 to 23, above.

As discussed herein, by having a coupled configuration and a decoupled configuration, variable camber trim unit 100 provides for selective coupling and decoupling of rotational movement of structures coupled to input gear 102 and output gear 108. Moreover, not only is output gear 108 rotationally decoupled from input gear 102 when variable camber trim unit 100 is in the decoupled configuration, but also output gear 108 is rotationally fixed relative to housing 124, which is desirable in some configurations of flight-control surfaces with which variable camber trim unit 100 is used in none or more examples.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 2-4 and 9 for illustrative purposes only and not by way of limitation, aircraft 300 is disclosed. Aircraft 300 comprises fuselage 306 and wing 308, supported by fuselage 306. Wing 308 comprises inboard flight-control surface 302, outboard flight-control surface 304, and variable camber trim unit 100. Inboard flight-control surface 302 is movable relative to fuselage 306. Outboard flight-control surface 304 is movable relative to fuselage 306. Variable camber trim unit 100 is coupled to inboard flight-control surface 302 and outboard flight-control surface 304. Variable camber trim unit 100 is selectively configurable to one of a coupled configuration or a decoupled configuration. When variable camber trim unit 100 is in the coupled configuration, outboard flight-control surface 304 is coupled to inboard flight-control surface 302, such that when inboard flight-control surface 302 moves relative to fuselage 306, outboard flight-control surface 304 also moves relative to fuselage 306. When variable camber trim unit 100 is in the decoupled configuration, outboard flight-control surface 304 is decoupled from inboard flight-control surface 302, such that when inboard flight-control surface 302 moves relative to the fuselage, outboard flight-control surface 304 is fixed relative to fuselage 306. The preceding portion of this paragraph characterizes example 25 of the subject matter, disclosed herein.

By having a coupled configuration and a decoupled configuration, variable camber trim unit 100 provides for selective coupling and decoupling of inboard flight-control surface 302 and outboard flight-control surface 304. Moreover, not only is outboard flight-control surface 304 decoupled from inboard flight-control surface 302 when variable camber trim unit 100 is in the decoupled configuration, but also outboard flight-control surface 304 is fixed relative to fuselage 306, which is desirable in some configurations of flight-control surfaces of aircraft 300.

With reference to FIGS. 8 and 9, in one or more examples, wing 308 further comprises power drive unit 310, input shaft 312 coupled between power drive unit 310 and input gear 102 of variable camber trim unit 100, inboard linkages 314 interconnecting input shaft 312 and inboard flight-control surface 302, output shaft 316 coupled to output gear 108 of variable camber trim unit 100, and outboard linkages 318 interconnecting output shaft 316 to outboard flight-control surface 304. Accordingly, when variable camber trim unit 100 is in the coupled configuration, rotation of input shaft 312 by power drive unit 310 causes inboard flight-control surface 302 to be deployed and also, via variable camber trim unit 100 and output shaft 316, causes outboard flight-control surface 304 to be deployed. When variable camber trim unit 100 is in the decoupled configuration, rotation of input shaft 312 by power drive unit 310 only causes inboard flight-control surface 302 to be deployed.

In one or more examples, variable camber trim unit 100 is configured to be installed in aircraft 300 for operation of any suitable type of inboard and outboard flight-control surfaces, examples of which include flaps, stabilizers, elevators, rudders, spoilers, slats, ailerons, and flaperons.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 comprises housing 124, input gear 102, output gear 108, input idler gear 104, output idler gear 106, and shaft 118. Input gear 102 is rotatably supported by housing 124 and is coupled to inboard flight-control surface 302. Output gear 108 is rotatably supported by housing 124 and is coupled to outboard flight-control surface 304. Input idler gear 104 is rotatably supported by housing 124, is meshed with input gear 102, and comprises input-idler-gear interior splined surface 110. Output idler gear 106 is rotatably supported by housing 124, is coaxial with input idler gear 104, is meshed with output gear 108, and comprises output-idler-gear interior splined surface. Shaft 118 is translationally supported within housing 124, is coaxial with input idler gear 104 and with output idler gear 106, and comprises first exterior splined surface 120, having a first-exterior-splined-surface maximum diameter, and second exterior splined surface 122, having a second-exterior-splined-surface maximum diameter. Housing 124 comprises anchor interior splined surface 116, coaxial with input idler gear 104 and with output idler gear 106. When variable camber trim unit 100 is in the coupled configuration, shaft 118 is positioned within housing 124, such that first exterior splined surface 120 of shaft 118 is engaged with input-idler-gear interior splined surface 110, first exterior splined surface 120 of shaft 118 is disengaged from anchor interior splined surface 116, and second exterior splined surface 122 of shaft 118 is engaged with output-idler-gear interior splined surface 112. When variable camber trim unit 100 is in the decoupled configuration, shaft 118 is positioned within housing 124, such that first exterior splined surface 120 of shaft 118 is disengaged from input-idler-gear interior splined surface 110, first exterior splined surface 120 of shaft 118 is engaged with anchor interior splined surface 116, and second exterior splined surface 122 of shaft 118 is engaged with output-idler-gear interior splined surface 112. The preceding portion of this paragraph characterizes example 26 of the subject matter, disclosed herein, wherein example 26 also encompasses example 25, above.

As discussed herein, input idler gear 104 and output idler gear 106 provide structure for transferring rotational input from input gear 102 to output gear 108, via shaft 118, when variable camber trim unit is in the coupled configuration. Shaft 118, via its exterior splines and their engagement with the interior splines of input idler gear 104, output idler gear 106, and housing 124 and via its translation within housing 124 enables the coupled and decoupled configurations of variable camber trim unit 100.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 2-4 for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 further comprises actuator 126, supported by housing 124 and configured to selectively translate shaft 118 from a retracted position, in which first exterior splined surface 120 is disengaged from anchor interior splined surface 116, to an extended position, in which first exterior splined surface 120 is engaged with anchor interior splined surface 116. The preceding portion of this paragraph characterizes example 27 of the subject matter, disclosed herein, wherein example 27 also encompasses example 26, above.

As discussed herein, by including actuator 126, variable camber trim unit 100 is controllable to transition variable camber trim unit 100 to its decoupled configuration when desired by a user or otherwise responsive to input from a control system, such as a flight control system.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 further comprises shaft spring 128, positioned within housing 124 and biasing shaft 118 toward the retracted position. The preceding portion of this paragraph characterizes example 28 of the subject matter, disclosed herein, wherein example 28 also encompasses example 27, above.

As discussed herein, by biasing shaft 118 toward its retracted position that thus variable camber trim unit 100 toward its coupled configuration, the coupled configuration is the default configuration. That is, selective actuation of actuator 126 causes variable camber trim unit 100 to transition to the decoupled configuration, and when actuator 126 is not actuated, shaft spring 128 causes variable camber trim unit 100 to transition to the coupled configuration.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, actuator 126 comprises cylinder 130 and actuator piston 132, positioned within cylinder 130 and operatively engaged with shaft 118. When cylinder 130 is pressurized, actuator piston 132 translates toward anchor interior splined surface 116 and causes shaft 118 to translate toward the extended position. The preceding portion of this paragraph characterizes example 29 of the subject matter, disclosed herein, wherein example 29 also encompasses example 27 or 28, above.

As discussed herein, by being pressure-actuated, variable camber trim unit 100 is controllable by a hydraulic or pneumatic system, such as a hydraulic system of an aircraft.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 further comprises pressure compensation chamber 166. Housing 124 comprises internal volume 170, within which shaft 118 is positioned. Pressure compensation chamber 166 is in fluidic communication with internal volume 170. When actuator piston 132 causes shaft 118 to translate toward the extended position, fluid from internal volume 170 flows into pressure compensation chamber 166. The preceding portion of this paragraph characterizes example 30 of the subject matter, disclosed herein, wherein example 30 also encompasses example 29, above.

As discussed herein, pressure compensation chamber 166 provides pressure relief within internal volume 170 when actuator piston 132 extends into internal volume 170. Accordingly, if a non-compressible fluid, such a lubricating fluid, is utilized within internal volume 170 for lubrication of the components of variable camber trim unit 100 within housing 124, a portion of the non-compressible fluid is displaced to pressure compensation chamber 166, thereby avoiding pressure spikes within housing 124 when variable camber trim unit 100 is in the decoupled configuration and thus maintaining integrity of any seals associated with housing 124.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, pressure compensation chamber 166 comprises chamber piston 172 and chamber spring 174, biasing chamber piston 172 toward internal volume 170. The preceding portion of this paragraph characterizes example 31 of the subject matter, disclosed herein, wherein example 31 also encompasses example 30, above.

As discussed herein, when variable camber trim unit 100 transitions to the decoupled configuration, fluid from internal volume 170 of housing 124 pushes against chamber piston 172 against the bias of chamber spring 174. As a result, a constant volume of the fluid is maintained. When variable camber trim unit 100 transitions to the coupled configuration, chamber spring 174 pushes chamber piston 172 toward internal volume 170 of housing 124 and thus pushes the fluid back into internal volume 170, again maintaining a constant volume of the fluid and maintaining integrity of any seals associated with housing 124.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 further comprises anchor aligner 134, positioned within housing 124 between input idler gear 104 and anchor interior splined surface 116. Anchor aligner 134 is configured to align first exterior splined surface 120 for engagement with anchor interior splined surface 116. The preceding portion of this paragraph characterizes example 32 of the subject matter, disclosed herein, wherein example 32 also encompasses any one of examples 26 to 31, above.

As discussed herein, anchor aligner 134 ensures that first exterior splined surface 120 of shaft 118 is aligned for operative engagement with anchor interior splined surface 116 so that variable camber trim unit 100 can transition from the coupled configuration to the decoupled configuration.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, in aircraft 300, anchor aligner 134 comprises aligner body 136 and aligner springs 138. Aligner body 136 is coaxial with shaft 118 and comprises aligner interior splined surface 140. Aligner springs 138 are engaged between aligner body 136 and housing 124 and rotationally bias aligner interior splined surface 140 into alignment with anchor interior splined surface 116 when aligner interior splined surface 140 is engaged with first exterior splined surface 120. The preceding portion of this paragraph characterizes example 33 of the subject matter, disclosed herein, wherein example 33 also encompasses example 32, above.

As discussed herein, by being rotationally spring-biased, aligner body 136 has a centering effect on shaft 118 when first exterior splined surface 120 is engaged with aligner interior splined surface 140 to ensure that first exterior splined surface 120 will operatively engage with anchor interior splined surface 116, and thus to ensure that variable camber trim unit 100 can transition to the decoupled configuration and effectively rotationally lock output gear 108 relative to housing 124. Accordingly, if variable camber trim unit 100 is configuring to the decoupled configuration and first exterior splined surface 120 is not precisely aligned for operative engagement with anchor interior splined surface 116, then anchor aligner 134 will rotate shaft 118 to ensure that first exterior splined surface 120 is aligned for operative engagement with anchor interior splined surface 116.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, in aircraft 300, aligner interior splined surface 140 comprises aligner-interior-splined-surface first end 142 and aligner-interior-splined-surface second end 144. Input idler gear 104 is closer to aligner-interior-splined-surface first end 142 than to aligner-interior-splined-surface second end 144. Splines of aligner interior splined surface 140 are tapered at aligner-interior-splined-surface first end 142. The preceding portion of this paragraph characterizes example 34 of the subject matter, disclosed herein, wherein example 34 also encompasses example 33, above.

As discussed herein, because the splines of aligner interior splined surface 140 are tapered at the first end, when variable camber trim unit 100 transitions to the decoupled configuration and shaft 118 translates toward anchor interior splined surface 116, anchor aligner 134 will accommodate first exterior splined surface 120 initially being misaligned with aligner interior splined surface 140. That is, the ends of the splines at the first end of aligner interior splined surface 140 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of aligner interior splined surface 140 as shaft 118 translates toward anchor interior splined surface 116.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, in aircraft 300, splines of aligner interior splined surface 140 are tapered at aligner-interior-splined-surface second end 144. The preceding portion of this paragraph characterizes example 35 of the subject matter, disclosed herein, wherein example 35 also encompasses example 34, above.

As discussed herein, because the splines of aligner interior splined surface 140 are tapered at the second end, when variable camber trim unit 100 transitions to the coupled configuration and shaft 118 translates away from anchor interior splined surface 116, anchor aligner 134 will accommodate first exterior splined surface 120 initially being misaligned with aligner interior splined surface 140. That is, the ends of the splines at the second end of aligner interior splined surface 140 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of aligner interior splined surface 140 as shaft 118 translates away from anchor interior splined surface 116.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, in aircraft 300, each spline of anchor interior splined surface 116 comprises tapered end 146, facing input idler gear 104. The preceding portion of this paragraph characterizes example 36 of the subject matter, disclosed herein, wherein example 36 also encompasses any one of examples 26 to 35, above.

As discussed herein, because the ends of the splines of anchor interior splined surface 116 are tapered, when variable camber trim unit 100 transitions to the decoupled configuration and shaft 118 translates toward anchor interior splined surface 116, housing 124 will accommodate first exterior splined surface 120 initially being misaligned with anchor interior splined surface 116. That is, the tapered ends of the splines of anchor interior splined surface 116 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of anchor interior splined surface 116 as shaft 118 translates toward anchor interior splined surface 116.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, in aircraft 300, each spline of input-idler-gear interior splined surface 110 comprises distal end 148, facing away from output idler gear 106. Distal end 148 is tapered. The preceding portion of this paragraph characterizes example 37 of the subject matter, disclosed herein, wherein example 37 also encompasses any one of examples 26 to 36, above.

As discussed herein, because the distal ends of the splines of input-idler-gear interior splined surface 110 are tapered, when variable camber trim unit 100 transitions to the coupled configuration and shaft 118 translates away from anchor interior splined surface 116, input idler gear 104 will accommodate first exterior splined surface 120 initially being misaligned with input-idler-gear interior splined surface 110. That is, the tapered distal ends of the splines of input-idler-gear interior splined surface 110 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the spines of input-idler-gear interior splined surface 110 as shaft 118 translates away anchor interior splined surface 116.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3-6 for illustrative purposes only and not by way of limitation, in aircraft 300, each spline of first exterior splined surface 120 comprises first-exterior-spline first end 150 and first-exterior-spline second end 152, spaced apart from each other. First-exterior-spline first end 150 is tapered, and first-exterior-spline second end 152 is tapered. The preceding portion of this paragraph characterizes example 38 of the subject matter, disclosed herein, wherein example 38 also encompasses any one of examples 26 to 37, above.

As discussed herein, because the first ends of the splines of first exterior splined surface 120 are tapered, when variable camber trim unit 100 transitions to the coupled configuration and shaft 118 translates away from anchor interior splined surface 116, shaft 118 will accommodate first exterior splined surface 120 initially being misaligned with input-idler-gear interior splined surface 110. That is, the first ends of the splines of first exterior splined surface 120 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of input-idler-gear interior splined surface 110 as shaft 118 translates away from anchor interior splined surface 116. Similarly, because the second ends of the splines of first exterior splined surface 120 are tapered, when variable camber trim unit 100 transitions to the decoupled configuration and shaft 118 translates toward anchor interior splined surface 116, the second ends of the splines of first exterior splined surface 120 serve as ramps to force the splines of first exterior splined surface 120 into operative engagement with the splines of anchor interior splined surface 116.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, shaft 118 extends through axial bore 154. Axial bore 154 comprises distal region 156, having a distal-region diameter, and proximal region 158, having a proximal-region diameter. Output idler gear 106 is closer to proximal region 158 than to distal region 156. Input-idler-gear interior splined surface 110 extends along only distal region 156 of axial bore 154. When variable camber trim unit 100 is in the decoupled configuration, second exterior splined surface 122 extends within proximal region 158 of axial bore 154. The preceding portion of this paragraph characterizes example 39 of the subject matter, disclosed herein, wherein example 39 also encompasses any one of examples 26 to 38, above.

As discussed herein, inclusion of proximal region 158 of axial bore 154 without input-idler-gear interior splined surface 110 enables input idler gear 104 and output idler gear 106 to be positioned in close proximity to each other within housing 124, thereby enabling variable camber trim unit 100 to be more compact.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, the proximal-region diameter is greater the second-exterior-splined-surface maximum diameter. The preceding portion of this paragraph characterizes example 40 of the subject matter, disclosed herein, wherein example 40 also encompasses example 39, above.

As discussed herein, by being greater in diameter than the second-exterior-splined-surface maximum diameter, proximal region 158 creates a volume, within which second exterior splined surface 122 extends without an interference or friction between second exterior splined surface 122 and input idler gear 104 when variable camber trim unit 100 is in the decoupled configuration.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, the proximal-region diameter is greater than the distal-region diameter. The preceding portion of this paragraph characterizes example 41 of the subject matter, disclosed herein, wherein example 41 also encompasses example 39 or 40, above.

As discussed herein, by having the proximal region greater in diameter than the distal-region diameter, in one or more examples, the maximum diameters of first exterior splined surface 120 and second exterior splined surface 122 of shaft 118 are the same, resulting in easier and lower-cost manufacture of shaft 118.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, the first-exterior-splined-surface maximum diameter is identical to the second-exterior-splined-surface maximum diameter. The preceding portion of this paragraph characterizes example 42 of the subject matter, disclosed herein, wherein example 42 also encompasses any one of examples 39 to 41, above.

As discussed herein, having the maximum diameters of first exterior splined surface 120 and second exterior splined surface 122 identical, shaft 118 is easier and less expensive to manufacture than otherwise.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, in aircraft 300, shaft 118 further comprises collar 160. When variable camber trim unit 100 is in the coupled configuration, collar 160 engages output idler gear 106. When variable camber trim unit 100 is in the decoupled configuration, collar 160 is positioned within proximal region 158. The preceding portion of this paragraph characterizes example 43 of the subject matter, disclosed herein, wherein example 43 also encompasses any one of examples 39 to 42, above.

As discussed herein, collar 160 acts as a structural stop to define the extent of translation of shaft 118 away from anchor interior splined surface 116. That is, engagement between collar 160 and output idler gear 106 at least in part defines the coupled configuration of variable camber trim unit 100. In one or more examples, actuator 126 therefore bears no force of shaft spring 128 when variable camber trim unit 100 is in the coupled configuration. In one or more examples, a gap is present between actuator piston 132 and shaft 118 when variable camber trim unit 100 is in the coupled configuration. Moreover, because collar 160 fits within proximal region 158 of axial bore 154 of input idler gear 104, variable camber trim unit 100 is compact.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIG. 3 for illustrative purposes only and not by way of limitation, in aircraft 300, shaft 118 further comprises collar 160. When variable camber trim unit 100 is in the coupled configuration, collar 160 engages output idler gear 106. The preceding portion of this paragraph characterizes example 44 of the subject matter, disclosed herein, wherein example 44 also encompasses any one of examples 26 to 42, above.

Again, collar 160 acts as a structural stop to define the extent of translation of shaft 118 away from anchor interior splined surface 116. That is, engagement between collar 160 and output idler gear 106 at least in part defines the coupled configuration of variable camber trim unit 100.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 2-5 for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 further comprises distal proximity sensor 162, supported by housing 124 and configured to sense when shaft 118 is less than a threshold distance away from distal proximity sensor 162. When shaft 118 is less than the threshold distance away from distal proximity sensor 162, first exterior splined surface 120 is engaged with anchor interior splined surface 116 and is disengaged from input-idler-gear interior splined surface 110. The preceding portion of this paragraph characterizes example 45 of the subject matter, disclosed herein, wherein example 45 also encompasses any one of examples 26 to 44, above.

As discussed herein, distal proximity sensor 162 provides a signal that confirms when variable camber trim unit 100 is in the decoupled configuration, and thus distal proximity sensor 162 enables notification of a potential non-operational state of variable camber trim unit 100, such as if variable camber trim unit 100 is otherwise intended to be in the coupled configuration.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIGS. 2-4 for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 further comprises proximal proximity sensor 164, supported by housing 124 and configured to sense when shaft 118 is less than a threshold distance away from proximal proximity sensor 164. When shaft 118 is less than the threshold distance away from proximal proximity sensor 164, first exterior splined surface 120 is disengaged from anchor interior splined surface 116 and is engaged with input-idler-gear interior splined surface 110. The preceding portion of this paragraph characterizes example 46 of the subject matter, disclosed herein, wherein example 46 also encompasses any one of examples 26 to 45, above.

As discussed herein, proximal proximity sensor 164 provides a signal that confirms when variable camber trim unit 100 is in the coupled configuration, and thus proximal proximity sensor 164 enables notification of a potential non-operational state of variable camber trim unit 100, such as if variable camber trim unit 100 is otherwise intended to be in the decoupled configuration.

Referring generally to FIGS. 1 and 8 and particularly to, e.g., FIG. 2_ for illustrative purposes only and not by way of limitation, in aircraft 300, variable camber trim unit 100 further comprises rotational position sensor 168, supported by housing 124 and configured to sense a rotational position of input gear 102 relative to housing 124. The preceding portion of this paragraph characterizes example 47 of the subject matter, disclosed herein, wherein example 47 also encompasses any one of examples 26 to 46, above.

As discussed herein, rotational position sensor 168 provides signal indicative of the rotational position of input gear 102 and thus also of upstream structure coupled to input gear 102, such as an inboard flight-control surface. Accordingly, the rotational position of the upstream structure is able to be monitored via merely sensing the rotational position of input gear 102, which is much less complex than directly sensing the rotational position of a large structure such as a flight-control surface.

Referring generally to FIG. 10 and particularly to, e.g., FIGS. 3 and 4 for illustrative purposes only and not by way of limitation, method 400 of operating aircraft 300 is disclosed. Method 400 comprises (block 402) configuring variable camber trim unit 100 of aircraft 300 to the coupled configuration and (block 404) configuring variable camber trim unit 100 to the decoupled configuration. The preceding portion of this paragraph characterizes example 48 of the subject matter, disclosed herein, wherein example 48 also encompasses any one of examples 25 to 47, above.

As discussed herein, by having a coupled configuration and a decoupled configuration, variable camber trim unit 100 provides for selective coupling and decoupling of inboard flight-control surface 302 and outboard flight-control surface 304. Moreover, not only is outboard flight-control surface 304 decoupled from inboard flight-control surface 302 when variable camber trim unit 100 is in the decoupled configuration, but also outboard flight-control surface 304 is fixed relative to fuselage 306, which is desirable in some configurations of flight-control surfaces of aircraft 300.

Examples of the subject matter, disclosed herein may be described in the context of aircraft manufacturing and service method 1100 as shown in FIG. 11 and aircraft 1102 as shown in FIG. 12. During pre-production, illustrative method 1100 may include specification and design (block 1104) of aircraft 1102 and material procurement (block 1106). During production, component and subassembly manufacturing (block 1108) and system integration (block 1110) of aircraft 1102 may take place. Thereafter, aircraft 1102 may go through certification and delivery (block 1112) to be placed in service (block 1114). While in service, aircraft 1102 may be scheduled for routine maintenance and service (block 1116). Routine maintenance and service may include modification, reconfiguration, refurbishment, etc. of one or more systems of aircraft 1102.

Each of the processes of illustrative method 1100 may be performed or carried out by a system integrator, a third party, and/or an operator (e.g., a customer). For the purposes of this description, a system integrator may include, without limitation, any number of aircraft manufacturers and major-system subcontractors; a third party may include, without limitation, any number of vendors, subcontractors, and suppliers; and an operator may be an airline, leasing company, military entity, service organization, and so on.

As shown in FIG. 12, aircraft 1102 produced by illustrative method 1100 may include airframe 1118 with a plurality of high-level systems 1120 and interior 1122. Examples of high-level systems 1120 include one or more of propulsion system 1124, electrical system 1126, hydraulic system 1128, and environmental system 1130. Any number of other systems may be included. Although an aerospace example is shown, the principles disclosed herein may be applied to other industries, such as the automotive industry. Accordingly, in addition to aircraft 1102, the principles disclosed herein may apply to other vehicles, e.g., land vehicles, marine vehicles, space vehicles, etc.

Apparatus(es) and method(s) shown or described herein may be employed during any one or more of the stages of the manufacturing and service method 1100. For example, components or subassemblies corresponding to component and subassembly manufacturing (block 1108) may be fabricated or manufactured in a manner similar to components or subassemblies produced while aircraft 1102 is in service (block 1114). Also, one or more examples of the apparatus(es), method(s), or combination thereof may be utilized during production stages 1108 and 1110, for example, by substantially expediting assembly of or reducing the cost of aircraft 1102. Similarly, one or more examples of the apparatus or method realizations, or a combination thereof, may be utilized, for example and without limitation, while aircraft 1102 is in service (block 1114) and/or during maintenance and service (block 1116).

Different examples of the apparatus(es) and method(s) disclosed herein include a variety of components, features, and functionalities. It should be understood that the various examples of the apparatus(es) and method(s), disclosed herein, may include any of the components, features, and functionalities of any of the other examples of the apparatus(es) and method(s) disclosed herein in any combination.

Many modifications of examples, set forth herein, will come to mind of one skilled in the art, having the benefit of the teachings, presented in the foregoing descriptions and the associated drawings.

Therefore, it is to be understood that the subject matter, disclosed herein, is not to be limited to the specific examples illustrated and that modifications and other examples are intended to be included within the scope of the appended claims. Moreover, although the foregoing description and the associated drawings describe examples of the subject matter, disclosed herein, in the context of certain illustrative combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative implementations without departing from the scope of the appended claims. Accordingly, parenthetical reference numerals in the appended claims are presented for illustrative purposes only and are not intended to limit the scope of the claimed subject matter to the specific examples provided herein. 

The invention claimed is:
 1. A variable camber trim unit, comprising: a housing; an input gear, rotatably supported by the housing; an output gear, rotatably supported by the housing; an input idler gear, rotatably supported by the housing, meshed with the input gear, and comprising an input-idler-gear interior splined surface; an output idler gear, rotatably supported by the housing, coaxial with the input idler gear, meshed with the output gear, and comprising an output-idler-gear interior splined surface; and a shaft, translationally supported within the housing, coaxial with the input idler gear and with the output idler gear, and comprising a first exterior splined surface, having a first-exterior-splined-surface maximum diameter, and a second exterior splined surface, having a second-exterior-splined-surface maximum diameter; wherein: the variable camber trim unit is selectively configurable to one of a coupled configuration or a decoupled configuration; when the variable camber trim unit is in the coupled configuration, rotation of the input gear relative to the housing causes rotation of the output gear relative to the housing; when the variable camber trim unit is in the decoupled configuration, rotation of the input gear relative to the housing does not cause rotation of the output gear, and the output gear is rotationally fixed relative to the housing; the housing comprises an anchor interior splined surface, coaxial with the input idler gear and with the output idler gear; when the variable camber trim unit is in the coupled configuration, the shaft is positioned within the housing, such that: the first exterior splined surface of the shaft is engaged with the input-idler-gear interior splined surface; the first exterior splined surface of the shaft is disengaged from the anchor interior splined surface; and the second exterior splined surface of the shaft is engaged with the output-idler-gear interior splined surface; and when the variable camber trim unit is in the decoupled configuration, the shaft is positioned within the housing, such that: the first exterior splined surface of the shaft is disengaged from the input-idler-gear interior splined surface; the first exterior splined surface of the shaft is engaged with the anchor interior splined surface; and the second exterior splined surface of the shaft is engaged with the output-idler-gear interior splined surface.
 2. The variable camber trim unit according to claim 1, further comprising an actuator, supported by the housing and configured to selectively translate the shaft from a retracted position, in which the first exterior splined surface is disengaged from the anchor interior splined surface, to an extended position, in which the first exterior splined surface is engaged with the anchor interior splined surface.
 3. The variable camber trim unit according to claim 2, further comprising a shaft spring, positioned within the housing and biasing the shaft toward the retracted position.
 4. The variable camber trim unit according to claim 2, wherein: the actuator comprises a cylinder and an actuator piston, positioned within the cylinder and operatively engaged with the shaft; and when the cylinder is pressurized, the actuator piston translates toward the anchor interior splined surface and causes the shaft to translate toward the extended position.
 5. The variable camber trim unit according to claim 4, further comprising a pressure compensation chamber; wherein: the housing comprises an internal volume, within which the shaft is positioned; the pressure compensation chamber is in fluidic communication with the internal volume; and when the actuator piston causes the shaft to translate toward the extended position, fluid from the internal volume flows into the pressure compensation chamber.
 6. The variable camber trim unit according to claim 5, wherein the pressure compensation chamber comprises a chamber piston and a chamber spring, biasing the chamber piston toward the internal volume.
 7. The variable camber trim unit according to claim 1, further comprising an anchor aligner, positioned within the housing between the input idler gear and the anchor interior splined surface and configured to align the first exterior splined surface for engagement with the anchor interior splined surface.
 8. The variable camber trim unit according to claim 7, wherein the anchor aligner comprises: an aligner body, coaxial with the shaft and comprising an aligner interior splined surface; and aligner springs, engaged between the aligner body and the housing and rotationally biasing the aligner interior splined surface into alignment with the anchor interior splined surface when the aligner interior splined surface is engaged with the first exterior splined surface.
 9. The variable camber trim unit according to claim 8, wherein: the aligner interior splined surface comprises an aligner-interior-splined-surface first end and an aligner-interior-splined-surface second end; the input idler gear is closer to the aligner-interior-splined-surface first end than to the aligner-interior-splined-surface second end; and splines of the aligner interior splined surface are tapered at the aligner-interior-splined-surface first end.
 10. The variable camber trim unit according to claim 9, wherein splines of the aligner interior splined surface are tapered at the aligner-interior-splined-surface second end.
 11. The variable camber trim unit according to claim 1, wherein each spline of the anchor interior splined surface comprises a tapered end, facing the input idler gear.
 12. The variable camber trim unit according to claim 1, wherein: each spline of the input-idler-gear interior splined surface comprises a distal end, facing away from the output idler gear; and the distal end is tapered.
 13. The variable camber trim unit according claim 1, wherein: each spline of the first exterior splined surface comprises a first-exterior-spline first end and a first-exterior-spline second end, spaced apart from each other; the first-exterior-spline first end is tapered; and the first-exterior-spline second end is tapered.
 14. The variable camber trim unit according to claim 1, wherein: the input idler gear further comprises an axial bore; the shaft extends through the axial bore; the axial bore comprises a distal region, having a distal-region diameter, and a proximal region, having a proximal-region diameter; the output idler gear is closer to the proximal region than to the distal region; the input-idler-gear interior splined surface extends along only the distal region of the axial bore; and when the variable camber trim unit is in the decoupled configuration, the second exterior splined surface extends within the proximal region of the axial bore.
 15. The variable camber trim unit according to claim 14, wherein the proximal-region diameter is greater than the second-exterior-splined-surface maximum diameter.
 16. The variable camber trim unit according to claim 14, wherein the proximal-region diameter is greater than the distal-region diameter.
 17. The variable camber trim unit according to claim 14, wherein the first-exterior-splined-surface maximum diameter is identical to the second-exterior-splined-surface maximum diameter.
 18. The variable camber trim unit according to claim 14, wherein: the shaft further comprises a collar; when the variable camber trim unit is in the coupled configuration, the collar engages the output idler gear; and when the variable camber trim unit is in the decoupled configuration, the collar is positioned within the proximal region.
 19. The variable camber trim unit according to claim 1, wherein: the shaft further comprises a collar; and when the variable camber trim unit is in the coupled configuration, the collar engages the output idler gear.
 20. A method of trimming flight-control surfaces, the method comprising configuring the variable camber trim unit according to claim 1 to the coupled configuration, and configuring the variable camber trim unit to the decoupled configuration.
 21. An aircraft, comprising: a fuselage; and a wing, supported by the fuselage and comprising: an inboard flight-control surface, movable relative to the fuselage; an outboard flight-control surface, movable relative to the fuselage; and the variable camber trim unit according to claim 1, coupled to the inboard flight-control surface and to the outboard flight-control surface; wherein: when the variable camber trim unit is in the coupled configuration, the outboard flight-control surface is coupled to the inboard flight-control surface, such that when the inboard flight-control surface moves relative to the fuselage, the outboard flight-control surface also moves relative to the fuselage; and when the variable camber trim unit is in the decoupled configuration, the outboard flight-control surface is decoupled from the inboard flight-control surface, such that when the inboard flight-control surface moves relative to the fuselage, the outboard flight-control surface is fixed relative to the fuselage.
 22. The variable camber trim unit according to claim 1, further comprising a distal proximity sensor, supported by the housing and configured to sense when the shaft is less than a threshold distance away from the distal proximity sensor, wherein, when the shaft is less than the threshold distance away from the distal proximity sensor, the first exterior splined surface is engaged with the anchor interior splined surface and is disengaged from the input-idler-gear interior splined surface.
 23. The variable camber trim unit according to claim 1, further comprising a proximal proximity sensor, supported by the housing and configured to sense when the shaft is less than a threshold distance away from the proximal proximity sensor, wherein, when the shaft is less than the threshold distance away from the proximal proximity sensor, the first exterior splined surface is disengaged from the anchor interior splined surface and is engaged with the input-idler-gear interior splined surface. 